126 lines
3.1 KiB
Markdown
126 lines
3.1 KiB
Markdown
# Tint diagnostic style guide
|
|
|
|
This guide provides a set of best practices when writing code that emits
|
|
diagnostic messages in Tint. These diagnostics are messages presented to the
|
|
user in case of error or warning.
|
|
|
|
The goal of this document is to have our diagnostic messages be clear and
|
|
understandable to our users, so that problems are easy to fix, and to try and
|
|
keep a consistent style.
|
|
|
|
## Message style
|
|
|
|
* Start diagnostic messages with a lower-case letter
|
|
* Try to keep the message to a single sentence, if possible
|
|
* Do not end the message with punctuation (full stop, exclamation mark, etc)
|
|
|
|
**Don't:**
|
|
|
|
```
|
|
shader.wgsl:7:1 error: Cannot take the address of expression.
|
|
```
|
|
|
|
**Do:**
|
|
|
|
```
|
|
shader.wgsl:7:1 error: cannot take the address of expression
|
|
```
|
|
|
|
**Justification:**
|
|
|
|
Succinct messages are more important than grammatical correctness. \
|
|
This style matches the style found in most other compilers.
|
|
|
|
## Prefer to use a `Source` location instead of quoting the code in the message
|
|
|
|
**Don't:**
|
|
|
|
```
|
|
shader.wgsl:5:7 error: structure 'UBO' requires block decoration
|
|
|
|
struct UBO {
|
|
^^^
|
|
```
|
|
|
|
**Do:**
|
|
|
|
```
|
|
shader.wgsl:5:7 error: structure requires block decoration
|
|
|
|
struct UBO {
|
|
^^^
|
|
```
|
|
|
|
**Justification:**
|
|
|
|
The highlighted line provides even more contextual information than the quoted
|
|
source, and duplicating this information doesn't provide any more help to the
|
|
developer.
|
|
|
|
## Use `note` diagnostics for providing additional links to relevant code
|
|
|
|
**Don't:**
|
|
|
|
```
|
|
shader.wgsl:5:11 error: type cannot be used in storage class 'storage' as it is non-host-shareable
|
|
|
|
cond : bool;
|
|
^^^^
|
|
```
|
|
|
|
**Do:**
|
|
|
|
```
|
|
shader.wgsl:5:11 error: type cannot be used in storage class 'storage' as it is non-host-shareable
|
|
|
|
cond : bool;
|
|
^^^^
|
|
|
|
shader.wgsl:8:4 note: while instantiating variable 'StorageBuffer'
|
|
|
|
var<storage> sb : StorageBuffer;
|
|
^^
|
|
```
|
|
|
|
**Justification:**
|
|
|
|
To properly understand some diagnostics requires looking at more than a single
|
|
line. \
|
|
Multi-source links can greatly reduce the time it takes to properly
|
|
understand a diagnostic message. \
|
|
This is especially important for diagnostics raised from complex whole-program
|
|
analysis, but can also greatly aid simple diagnostics like symbol collision errors.
|
|
|
|
## Use simple terminology
|
|
|
|
**Don't:**
|
|
|
|
```
|
|
shader.wgsl:7:1 error: the originating variable of the left-hand side must not have an access(read) access attribute.
|
|
```
|
|
|
|
**Do:**
|
|
|
|
```
|
|
shader.wgsl:7:1 error: cannot assign to variable with [[access(read)]] decoration
|
|
|
|
x = 1;
|
|
^
|
|
|
|
shader.wgsl:2:8 note: [[access(read)]] declared here
|
|
|
|
var x : [[access(read)]] i32;
|
|
^^^^^^^^^^^^^^^^
|
|
```
|
|
|
|
**Justification:**
|
|
|
|
Diagnostics will be read by Web developers who may not be native English
|
|
speakers and are unlikely to be familiar with WGSL specification terminology.
|
|
Too much technical jargon can be intimidating and confusing. \
|
|
Diagnostics should give enough information to explain what's wrong, and most
|
|
importantly, give enough information so that a fix actionable.
|
|
|
|
**Caution:** Be careful to not over simplify. Use the specification terminology
|
|
if there's potential ambiguity by not including it.
|